MDEV-38591: Address latest grooverdan review feedback

- Section 11: use LONGTEXT instead of JSON column to avoid dependency on
  check_constraint_checks which will be disabled in PR MariaDB#5263
- Remove remaining SHOW WARNINGS from section 13.7 (MTR outputs warnings
  automatically)
- Remove '(mentor)' annotations from echo labels in sections 15, 19, 20
- NULL candidate semantics: remove args[0]->null_value check, allowing
  NULL MEMBER OF ('[null]') = 1 (SQL NULL treated as JSON null via
  json_quote_item returning 'null' per MDEV-13645). Intentional divergence
  from MySQL documented behavior per grooverdan's request.
- Simplify stored function tests: single-line CREATE FUNCTION without
  delimiters, positive VARCHAR test (f() RETURNS VARCHAR), JSON-returning
  function test (j_row_result() RETURNS JSON)
- Add optimizer trace test (section 22) showing MEMBER OF participates
  correctly in equality_propagation and condition_processing
- Add set_maybe_null() in fix_length_and_dec() for cursor protocol
  compatibility per grooverdan

Author: kjarir

mysql-test/suite/json/r/member_of.result

@@ -22,10 +22,10 @@ SELECT 2 MEMBER OF ('["1","2","3"]');
 # 4. SQL NULL propagation checks
 SELECT NULL MEMBER OF ('[1,2,3]');
 NULL MEMBER OF ('[1,2,3]')
-NULL
+0
 SELECT NULL MEMBER OF ('[1,2,3]') IS NULL;
 NULL MEMBER OF ('[1,2,3]') IS NULL
-1
+0
 SELECT 1 MEMBER OF (NULL);
 1 MEMBER OF (NULL)
 NULL
@@ -71,17 +71,17 @@ id	val	2 MEMBER OF (val)
 3	NULL	NULL
 SELECT id, val, NULL MEMBER OF (val) FROM t1;
 id	val	NULL MEMBER OF (val)
-1	[1, 2, 3]	NULL
-2	[4, 5, 6]	NULL
+1	[1, 2, 3]	0
+2	[4, 5, 6]	0
 3	NULL	NULL
 CREATE TABLE t2 (candidate INT);
 INSERT INTO t2 VALUES (2), (4), (NULL);
 SELECT candidate, val, candidate MEMBER OF (val) FROM t1, t2 ORDER BY id, candidate;
 candidate	val	candidate MEMBER OF (val)
-NULL	[1, 2, 3]	NULL
+NULL	[1, 2, 3]	0
 2	[1, 2, 3]	1
 4	[1, 2, 3]	0
-NULL	[4, 5, 6]	NULL
+NULL	[4, 5, 6]	0
 2	[4, 5, 6]	0
 4	[4, 5, 6]	1
 NULL	NULL	NULL
@@ -112,14 +112,12 @@ EXECUTE stmt2 USING @candidate_json, @container_nested;
 JSON_COMPACT(?) MEMBER OF (?)
 1
 DEALLOCATE PREPARE stmt2;
-# 11. Malformed JSON-typed candidate test (using CHECK constraints bypass)
-CREATE TABLE t3 (val JSON);
-SET STATEMENT check_constraint_checks=0 FOR INSERT INTO t3 VALUES ('[1,2');
+# 11. Malformed LONGTEXT candidate test
+CREATE TABLE t3 (val LONGTEXT);
+INSERT INTO t3 VALUES ('[1,2');
 SELECT val MEMBER OF ('[1,2,3]') FROM t3;
 val MEMBER OF ('[1,2,3]')
-NULL
-Warnings:
-Warning	4037	Unexpected end of JSON text in argument 2 to function 'json_contains'
+0
 DROP TABLE t3;
 # 12. JSON scalar candidate test (type-strictness in passthrough branch)
 CREATE TABLE t4 (val JSON);
@@ -142,13 +140,13 @@ SELECT 4 NOT MEMBER OF ('[1,2,3]');
 SELECT '2' NOT MEMBER OF ('[1,2,3]');
 '2' NOT MEMBER OF ('[1,2,3]')
 1
-# 13.4 NULL NOT MEMBER OF ('[1,2,3]') -> NULL (and IS NULL -> 1)
+# 13.4 NULL NOT MEMBER OF ('[1,2,3]') -> 1
 SELECT NULL NOT MEMBER OF ('[1,2,3]');
 NULL NOT MEMBER OF ('[1,2,3]')
-NULL
+1
 SELECT NULL NOT MEMBER OF ('[1,2,3]') IS NULL;
 NULL NOT MEMBER OF ('[1,2,3]') IS NULL
-1
+0
 # 13.5 1 NOT MEMBER OF (NULL) -> NULL (and IS NULL -> 1)
 SELECT 1 NOT MEMBER OF (NULL);
 1 NOT MEMBER OF (NULL)
@@ -168,9 +166,6 @@ id	select_type	table	type	possible_keys	key	key_len	ref	rows	filtered	Extra
 1	SIMPLE	NULL	NULL	NULL	NULL	NULL	NULL	NULL	NULL	No tables used
 Warnings:
 Note	1003	select 1 not member of ('[1,2,3]') AS `1 NOT MEMBER OF ('[1,2,3]')`
-SHOW WARNINGS;
-Level	Code	Message
-Note	1003	select 1 not member of ('[1,2,3]') AS `1 NOT MEMBER OF ('[1,2,3]')`
 # 14. Prepared Statements twice execution for Section 6 nested cases
 PREPARE stmt3 FROM 'SELECT JSON_COMPACT(\'[1,2]\') MEMBER OF (\'[[1,2],[3,4]]\')';
 EXECUTE stmt3;
@@ -189,24 +184,24 @@ JSON_COMPACT('{"name":"John"}') MEMBER OF ('[{"name":"John"},{"name":"Joe"}]')
 1
 DEALLOCATE PREPARE stmt4;
 #
-# 15. Item 12 (mentor): null literal vs JSON null \u2014 type-strict distinctions
+# 15. null literal vs JSON null — type-strict distinctions
 #
 # SQL string 'null' inside a JSON string-array ["null"] -> 1 (matches the string)
 select 'null' member of ('["null"]');
 'null' member of ('["null"]')
 1
-# SQL NULL inside an array containing JSON null literal [null] -> NULL (SQL NULL propagates)
+# SQL NULL inside an array containing JSON null literal [null] -> 1
 select null member of ('[null]');
 null member of ('[null]')
-NULL
+1
 # SQL string 'null' inside an array containing JSON null literal [null] -> 0 (type mismatch)
 select 'null' member of ('[null]');
 'null' member of ('[null]')
 0
-# SQL NULL inside a JSON string-array ["null"] -> NULL (SQL NULL propagates)
+# SQL NULL inside a JSON string-array ["null"] -> 0 (type mismatch)
 select null member of ('["null"]');
 null member of ('["null"]')
-NULL
+0
 #
 # 16. Regression test for Item 1 root-cause fix (stale a2_parsed cache bug)
 # Before the fix, cross-join with non-constant candidate produced wrong results:
@@ -220,15 +215,15 @@ INSERT INTO t5 VALUES (1, '[1, 2, 3]'), (2, '[4, 5, 6]'), (3, NULL);
 CREATE TABLE t6 (candidate INT);
 INSERT INTO t6 VALUES (2), (4), (NULL);
 # Exact results expected after fix:
-# (NULL, [1,2,3]) -> NULL, (2, [1,2,3]) -> 1, (4, [1,2,3]) -> 0
-# (NULL, [4,5,6]) -> NULL, (2, [4,5,6]) -> 0, (4, [4,5,6]) -> 1
+# (NULL, [1,2,3]) -> 0, (2, [1,2,3]) -> 1, (4, [1,2,3]) -> 0
+# (NULL, [4,5,6]) -> 0, (2, [4,5,6]) -> 0, (4, [4,5,6]) -> 1
 # (NULL, NULL)    -> NULL, (2, NULL)    -> NULL, (4, NULL)  -> NULL
 SELECT candidate, val, candidate MEMBER OF (val) FROM t5, t6 ORDER BY id, candidate;
 candidate	val	candidate MEMBER OF (val)
-NULL	[1, 2, 3]	NULL
+NULL	[1, 2, 3]	0
 2	[1, 2, 3]	1
 4	[1, 2, 3]	0
-NULL	[4, 5, 6]	NULL
+NULL	[4, 5, 6]	0
 2	[4, 5, 6]	0
 4	[4, 5, 6]	1
 NULL	NULL	NULL
@@ -271,22 +266,23 @@ a	j	k	t7.a MEMBER OF (t8.k)
 1	[1,2,3]	[1,2,3]	1
 DROP TABLE t7, t8;
 #
-# 19. Item 6 (mentor): Single-column ROW_RESULT via stored function call
-# Stored function calls (Item_func_sp) report ROW_RESULT with cols() == 1
-# at the point val_str() inspects args[0]->result_type() — the goto-eval unwrap
-# path is reached through ordinary stored function calls.
+# 19. Stored function tests (VARCHAR and JSON return types)
 #
-CREATE FUNCTION f_row_result() RETURNS VARCHAR(50)
-RETURN JSON_OBJECT('value', 2, 'key', 'golden')//
-SELECT f_row_result() MEMBER OF ('[{"key": "golden", "value": 2E0}]');
-f_row_result() MEMBER OF ('[{"key": "golden", "value": 2E0}]')
+CREATE FUNCTION f() RETURNS VARCHAR(30) RETURN 'pony';
+SELECT f() MEMBER OF ('["sheep", "lamb", "pony"]');
+f() MEMBER OF ('["sheep", "lamb", "pony"]')
+1
+SELECT JSON_QUOTE(f());
+JSON_QUOTE(f())
+"pony"
+DROP FUNCTION f;
+CREATE FUNCTION j_row_result() RETURNS JSON RETURN JSON_OBJECT('value', 2, 'key', 'golden');
+SELECT j_row_result() MEMBER OF ('[{"key": "golden", "value": 2E0}]');
+j_row_result() MEMBER OF ('[{"key": "golden", "value": 2E0}]')
 0
-SELECT JSON_QUOTE(f_row_result());
-JSON_QUOTE(f_row_result())
-"{\"value\": 2, \"key\": \"golden\"}"
-DROP FUNCTION f_row_result;
+DROP FUNCTION j_row_result;
 #
-# 20. Item 4 (mentor): TIME_RESULT tests
+# 20. TIME_RESULT tests
 # Verify that TIME values are quoted as JSON string literals without escaping.
 #
 SELECT JSON_QUOTE(CAST('12:30:00' AS TIME));
@@ -303,12 +299,41 @@ CAST('12:30:00' AS TIME) MEMBER OF ('["10:00:00", "12:30:00"]')
 # Confirms literal multi-column ROW() constructors and RETURNS ROW(...) functions
 # are rejected by check_cols(1) during fix_fields() at bind time.
 #
-CREATE FUNCTION f1_row() RETURNS ROW(a INT)
-BEGIN
-RETURN (SELECT 42);
-END//
+CREATE FUNCTION f1_row() RETURNS ROW(a INT) RETURN (SELECT 42);
 SELECT JSON_QUOTE(f1_row());
 ERROR 21000: Operand should contain 1 column(s)
 SELECT f1_row() MEMBER OF ('[42]');
 ERROR 21000: Operand should contain 1 column(s)
 DROP FUNCTION f1_row;
+#
+# 22. Optimizer trace test for condition processing
+#
+CREATE TABLE t (id INT PRIMARY KEY, x INT, j JSON);
+INSERT INTO t VALUES (1, 10, '[10, 20]'), (2, 20, '[10, 20]'), (3, 30, '[30, 40]');
+SET STATEMENT optimizer_trace='enabled=on' FOR SELECT * FROM t WHERE x=10 AND x MEMBER OF (j);
+id	x	j
+1	10	[10, 20]
+SELECT JSON_DETAILED(JSON_EXTRACT(TRACE, '$**.condition_processing')) AS t FROM information_schema.OPTIMIZER_TRACE;
+t
+[
+    {
+        "condition": "WHERE",
+        "original_condition": "t.x = 10 and t.x member of (t.j)",
+        "steps": 
+        [
+            {
+                "transformation": "equality_propagation",
+                "resulting_condition": "10 member of (t.j) and multiple equal(10, t.x)"
+            },
+            {
+                "transformation": "constant_propagation",
+                "resulting_condition": "10 member of (t.j) and multiple equal(10, t.x)"
+            },
+            {
+                "transformation": "trivial_condition_removal",
+                "resulting_condition": "10 member of (t.j) and multiple equal(10, t.x)"
+            }
+        ]
+    }
+]
+DROP TABLE t;

mysql-test/suite/json/t/member_of.test

@@ -65,9 +65,9 @@ EXECUTE stmt2 USING @candidate_json, @container_nested;
 EXECUTE stmt2 USING @candidate_json, @container_nested;
 DEALLOCATE PREPARE stmt2;
 
---echo # 11. Malformed JSON-typed candidate test (using CHECK constraints bypass)
-CREATE TABLE t3 (val JSON);
-SET STATEMENT check_constraint_checks=0 FOR INSERT INTO t3 VALUES ('[1,2');
+--echo # 11. Malformed LONGTEXT candidate test
+CREATE TABLE t3 (val LONGTEXT);
+INSERT INTO t3 VALUES ('[1,2');
 SELECT val MEMBER OF ('[1,2,3]') FROM t3;
 DROP TABLE t3;
 
@@ -87,7 +87,7 @@ SELECT 4 NOT MEMBER OF ('[1,2,3]');
 --echo # 13.3 '2' NOT MEMBER OF ('[1,2,3]') -> 1 (type-strict comparison)
 SELECT '2' NOT MEMBER OF ('[1,2,3]');
 
---echo # 13.4 NULL NOT MEMBER OF ('[1,2,3]') -> NULL (and IS NULL -> 1)
+--echo # 13.4 NULL NOT MEMBER OF ('[1,2,3]') -> 1
 SELECT NULL NOT MEMBER OF ('[1,2,3]');
 SELECT NULL NOT MEMBER OF ('[1,2,3]') IS NULL;
 
@@ -100,7 +100,6 @@ SELECT 1 NOT MEMBER OF ('not_json');
 
 --echo # 13.7 EXPLAIN EXTENDED round-trip print check
 EXPLAIN EXTENDED SELECT 1 NOT MEMBER OF ('[1,2,3]');
-SHOW WARNINGS;
 
 
 --echo # 14. Prepared Statements twice execution for Section 6 nested cases
@@ -115,15 +114,15 @@ EXECUTE stmt4;
 DEALLOCATE PREPARE stmt4;
 
 --echo #
---echo # 15. Item 12 (mentor): null literal vs JSON null \u2014 type-strict distinctions
+--echo # 15. null literal vs JSON null — type-strict distinctions
 --echo #
 --echo # SQL string 'null' inside a JSON string-array ["null"] -> 1 (matches the string)
 select 'null' member of ('["null"]');
---echo # SQL NULL inside an array containing JSON null literal [null] -> NULL (SQL NULL propagates)
+--echo # SQL NULL inside an array containing JSON null literal [null] -> 1
 select null member of ('[null]');
 --echo # SQL string 'null' inside an array containing JSON null literal [null] -> 0 (type mismatch)
 select 'null' member of ('[null]');
---echo # SQL NULL inside a JSON string-array ["null"] -> NULL (SQL NULL propagates)
+--echo # SQL NULL inside a JSON string-array ["null"] -> 0 (type mismatch)
 select null member of ('["null"]');
 
 --echo #
@@ -140,8 +139,8 @@ CREATE TABLE t6 (candidate INT);
 INSERT INTO t6 VALUES (2), (4), (NULL);
 
 --echo # Exact results expected after fix:
---echo # (NULL, [1,2,3]) -> NULL, (2, [1,2,3]) -> 1, (4, [1,2,3]) -> 0
---echo # (NULL, [4,5,6]) -> NULL, (2, [4,5,6]) -> 0, (4, [4,5,6]) -> 1
+--echo # (NULL, [1,2,3]) -> 0, (2, [1,2,3]) -> 1, (4, [1,2,3]) -> 0
+--echo # (NULL, [4,5,6]) -> 0, (2, [4,5,6]) -> 0, (4, [4,5,6]) -> 1
 --echo # (NULL, NULL)    -> NULL, (2, NULL)    -> NULL, (4, NULL)  -> NULL
 SELECT candidate, val, candidate MEMBER OF (val) FROM t5, t6 ORDER BY id, candidate;
 
@@ -181,23 +180,19 @@ SELECT t7.a, t7.j, t8.k, t7.a MEMBER OF (t8.k) FROM t7, t8
 DROP TABLE t7, t8;
 
 --echo #
---echo # 19. Item 6 (mentor): Single-column ROW_RESULT via stored function call
---echo # Stored function calls (Item_func_sp) report ROW_RESULT with cols() == 1
---echo # at the point val_str() inspects args[0]->result_type() — the goto-eval unwrap
---echo # path is reached through ordinary stored function calls.
+--echo # 19. Stored function tests (VARCHAR and JSON return types)
 --echo #
---delimiter //
-CREATE FUNCTION f_row_result() RETURNS VARCHAR(50)
-RETURN JSON_OBJECT('value', 2, 'key', 'golden')//
---delimiter ;
+CREATE FUNCTION f() RETURNS VARCHAR(30) RETURN 'pony';
+SELECT f() MEMBER OF ('["sheep", "lamb", "pony"]');
+SELECT JSON_QUOTE(f());
+DROP FUNCTION f;
 
-SELECT f_row_result() MEMBER OF ('[{"key": "golden", "value": 2E0}]');
-SELECT JSON_QUOTE(f_row_result());
-
-DROP FUNCTION f_row_result;
+CREATE FUNCTION j_row_result() RETURNS JSON RETURN JSON_OBJECT('value', 2, 'key', 'golden');
+SELECT j_row_result() MEMBER OF ('[{"key": "golden", "value": 2E0}]');
+DROP FUNCTION j_row_result;
 
 --echo #
---echo # 20. Item 4 (mentor): TIME_RESULT tests
+--echo # 20. TIME_RESULT tests
 --echo # Verify that TIME values are quoted as JSON string literals without escaping.
 --echo #
 SELECT JSON_QUOTE(CAST('12:30:00' AS TIME));
@@ -209,12 +204,7 @@ SELECT CAST('12:30:00' AS TIME) MEMBER OF ('["10:00:00", "12:30:00"]');
 --echo # Confirms literal multi-column ROW() constructors and RETURNS ROW(...) functions
 --echo # are rejected by check_cols(1) during fix_fields() at bind time.
 --echo #
---delimiter //
-CREATE FUNCTION f1_row() RETURNS ROW(a INT)
-BEGIN
-  RETURN (SELECT 42);
-END//
---delimiter ;
+CREATE FUNCTION f1_row() RETURNS ROW(a INT) RETURN (SELECT 42);
 
 --error ER_OPERAND_COLUMNS
 SELECT JSON_QUOTE(f1_row());
@@ -223,3 +213,11 @@ SELECT f1_row() MEMBER OF ('[42]');
 
 DROP FUNCTION f1_row;
 
+--echo #
+--echo # 22. Optimizer trace test for condition processing
+--echo #
+CREATE TABLE t (id INT PRIMARY KEY, x INT, j JSON);
+INSERT INTO t VALUES (1, 10, '[10, 20]'), (2, 20, '[10, 20]'), (3, 30, '[30, 40]');
+SET STATEMENT optimizer_trace='enabled=on' FOR SELECT * FROM t WHERE x=10 AND x MEMBER OF (j);
+SELECT JSON_DETAILED(JSON_EXTRACT(TRACE, '$**.condition_processing')) AS t FROM information_schema.OPTIMIZER_TRACE;
+DROP TABLE t;

sql/item_jsonfunc.cc

@@ -6703,23 +6703,16 @@ bool Item_func_member_of::val_bool()
 {
   DBUG_ASSERT(fixed());
 
-  /*
-    Item 11: Evaluated json_contains_item directly. The previous check
-      if (is_json_type(args[0])) { args[0]->val_json(&tmp_candidate); ... }
-    was redundant because json_contains_item->val_bool() evaluates args[0]
-    (passed directly as args[1] of json_contains_item when is_json_type is true)
-    and sets json_contains_item->null_value appropriately.
-  */
   bool res= json_contains_item->val_bool();
   /*
-    Item 8: json_contains_item->null_value must be checked first.  It is only
-    after Item_json_contains::val_bool() runs that args[0] (wrapped inside
-    json_contains_item as args[1] of that call, possibly via
-    Item_func_json_quote) has actually been evaluated via val_json().
-    Checking args[0]->null_value before json_contains_item->val_bool() has
-    been called would read a stale/unset null_value from the previous row.
+    Note: MariaDB intentionally diverges from MySQL's documented behavior
+    ("If value is NULL, returns NULL"). MariaDB evaluates SELECT NULL MEMBER OF
+    ('[null]') as 1 and SELECT NULL MEMBER OF ('[1,2,3]') as 0. When args[0] is
+    SQL NULL, json_quote_item returns the string "null" (per MDEV-13645), which
+    json_contains_item matches against JSON null in the array. Container NULL
+    (args[1] IS NULL) still propagates SQL NULL via json_contains_item->null_value.
   */
-  if (json_contains_item->null_value || args[0]->null_value)
+  if (json_contains_item->null_value)
   {
     null_value= 1;
     return false;
@@ -6740,6 +6733,8 @@ bool Item_func_member_of::fix_length_and_dec(THD *thd)
   if (Item_func_opt_neg::fix_length_and_dec(thd))
     return true;
 
+  set_maybe_null();
+
   List<Item> contains_args;
   if (contains_args.push_back(args[1], thd->mem_root))
     return true;